Firefighters sealed off a building in Edinburgh on Wednesday after three packages suspected to contain radioactive materials were discovered, emergency services said.

A box containing packets labelled "strontium", "radium" and "plutonium" was found in a cupboard in a language school in the centre of the city, but officials said there was no cause for alarm and that the materials were probably of low radiation.

"There's no intelligence to suggest anything bad," said Jim Fraser, a spokesman for the local fire brigade, which sealed off the building after the materials were discovered.

"There are signs on the packages suggesting that they contain radioactive materials, but most schools have these sorts of materials for chemistry experiments and that sort of thing and it's really, really low risk."

He said radiation experts were on the scene and would use specialist equipment just to make sure there was no danger.